The Sock Guy People for Bikes Socks are made with 75% Ultra-wicking Micro Denier Acrylic, 15% Nylon and 10% Spandex for exceptional comfort and strength. All Sock Guy cycling socks feature the "Stretch-To-Fit" sizing system and their exclusive "Easy-Fit" cuff for a perfect fit every time on any foot. Sock Guy Cycling Socks delivery superior quality and high-tech comfort in every sock they make. Guaranteed! There is a double stitched heel & toe for added strength and durability. Superior quality, high tech comfort, what else do you need?